Evolution of the Turboprop for High Speed Air Transportation

1978 ◽  
Author(s):  
G. E. Holbrook ◽  
G. Rosen
Keyword(s):  
Fuel Consumption ◽  
Noise Level ◽  
High Speed ◽  
Cost Effective ◽  
Air Transportation ◽  
Low Noise ◽  
The Other ◽  
Propulsion Systems ◽  
Maintenance Costs ◽  
Passenger Comfort

Since they first entered military and commercial service during the 1950’s, U.S.-manufactured turbopropeller engines have proved to be reliable, fuel-efficient propulsion systems for aircraft. Despite their somewhat greater mechanical complexity when comprared with turbofans, the repair and maintenance costs of the turboprops compare very favorably with those of the other types, and their substantially reduced fuel consumption and low noise level merit serious consideration for aircraft in an energy and environmentally critical future. Advancements in propeller/fan aerodynamic and structural technologies now permit flight speeds up to Mach 0.85, making turly cost-effective aircraft possible, while retaining present standards of passenger comfort and powerplant reliability.

Study on Noise in New Roller Chain Drives

2012 ◽  
Vol 522 ◽  
pp. 598-601
Author(s):  
Wei Sun ◽  
Xiao Lun Liu ◽  
Wen Cheng Wang ◽  
Li Yan He ◽  
Jia Jun Liu
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
High Speed ◽  
Low Noise ◽  
The Other ◽  
Metal Mesh ◽  
Roller Chain ◽  
Polyurethane Composite ◽  
Noise Characteristics ◽  
The Impact

In order to mitigate the impact and the polygon effect of the chain and the sprocket during the meshing process and achieve the purpose of noise reduction, a Hlow noiseH nanostructured metal mesh-polyurethane composite material split roller chain was designed by means of changing structure and material of chain roller. Noise testing and frequency spectrum analysis were conducted, for the new roller chain and the other three kinds of the same specification chains with different structural rollers, on the closed force flow noise test bench researched and developed independently. The results show that the new roller chain can absorb some of the impact energy, and reduce vibration and noise of chain drive. The noise level generated by the new roller chain is significantly lower than the other tested roller chains, especially in high frequency and high speed. The difference in noise level is actually 3-11dB in driving sprocket speed of 1000r/min, and a significant noise reduction is achieved. The results also verify low noise characteristics of the new roller chain and rationality of design method.

scholarly journals Design and Operational Innovations in Adapting the Existing Merchant River Fleet to Cost-Effective Shipping

2019 ◽  
Vol 26 (4) ◽  
pp. 157-164 ◽  
Author(s):  
Teresa Abramowicz-Gerigk ◽  
Zbigniew Burciu
Keyword(s):  
Air Pollution ◽  
Fuel Consumption ◽  
Cost Effective ◽  
Progressive Decrease ◽  
Propulsion Systems ◽  
Local Conditions ◽  
River Transport ◽  
Multimodal Transport ◽  
Smart Technologies ◽  
Minimum Costs

Abstract Modernisation of the existing river fleet adapted for the local conditions of the Middle and Lower Vistula can be considered as a solution to slow down the progressive decrease of river transport in this area. The implementation of technical improvements, smart technologies and enhancement of transport performance may partially solve the problem of growing demand for multimodal transport of containers and oversized loads in a shorter perspective than the expected period of planned revitalisation of the river. The paper presents investigations on the modernisation of river convoys adapted to the current navigational conditions of the Lower Vistula. The different options have been discussed by the authors with river fleet operators and the best recognised solution was agreed to be the use of river convoys combining modernised motor barges and the pushed barges previously used in this area. Improvement of the transport profitability, reduction of fuel consumption, air pollution and noise can be achieved at minimum costs by modernisation of the main power-propulsion systems of outdated motor barges and the implementation of innovative steering systems on pushed barges. The demand for power-propulsion and manoeuvring performance of modernised convoys is discussed in the paper.

Study of Aerodynamics on Indian Budget Concept Car

2020 ◽  
Vol 12 (5) ◽  
Author(s):  
Lakshay Khera ◽  
Niraj Kumar ◽  
Ambrish Maurya
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Lift Force ◽  
Aerodynamic Drag ◽  
Cost Effective ◽  
Medium Size ◽  
Technical Knowledge ◽  
Aerodynamic Design ◽  
Ansys Fluent ◽  
Computer Knowledge

Currently demand of Indian budget cars also called people’s car in India is in great demand and around 1 million cars have been sold in the last financial year with 12% increase of sales in every forthcoming year. These are categorized in sub 4m category of sedan, hatchbacks and medium size SUVs’ and their price ranges between 7 to 11 lakhs. The aerodynamics significantly affects the performance of the vehicle particularly at high speed. The manufactures are more focused on styling and giving a luxury look and other features of the car which sometimes make them to compromise on its aerodynamic design. This may lead to increase in fuel consumption at Indian road conditions. A cost-effective way to reduce fuel consumption, drag coefficient, lift force is to improve aerodynamic behavior and reduce the aerodynamic drag. The software used in this work is Solidworks, Ansys Fluent and commercial CFD post. Consequently, of using this software, it allows us to apply, learn and link technical knowledge of aerodynamics and computer knowledge.

Test and Analysis of Bush Roller Chains for Noise Reduction

2011 ◽  
Vol 52-54 ◽  
pp. 430-435
Author(s):  
Xiao Lun Liu ◽  
Wei Sun ◽  
Song Ding ◽  
Jian Fang Liu ◽  
Yu Ying Wang ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Impact Energy ◽  
Noise Level ◽  
Low Noise ◽  
Working Environment ◽  
The Other ◽  
Chain Drive ◽  
Noise Characteristics ◽  
Testing Data ◽  
Different Types

A low noise duplex bush chains with split rollers was developed through changing roller structure to reduce noise of bush roller chains. The split rollers could absorb more impact energy, mitigate meshing impact and reduce chain drive noise. The noise generated by different types of duplex bush roller chains was carried out to test in same speed, low noise characteristics of duplex sleeve chains with split rollers was verified. By analysis of testing data, noise level of duplex sleeve chains with split rollers compared with that of the other duplex bush roller chains was reduced by the average 3 ~ 8dB, and low 10 ~ 13dB than that of 16A simplex sleeve roller chains. The chains made chain drive significantly improve in the working environment, with steady transmission, strong bearing, low noise, and a significant noise reduction was achieved.

scholarly journals Study of Parallel Algorithms for IP Switches

2019 ◽  
Vol 24 (2) ◽  
pp. 158-163
Author(s):  
Mhnd Farhan
Keyword(s):  
Parallel Algorithms ◽  
High Speed ◽  
Linear Time ◽  
Low Cost ◽  
Cost Effective ◽  
Internet Traffic ◽  
The Other ◽  
The Internet ◽  
Large Capacity ◽  
Internet Connectivity

Abstract Owing to the increase in the internet traffic, any calculation that requires more than linear time would be considered unreasonably moderate for constant applications. One cure is to utilize numerous processors to build up associations in parallel and the other is to construct low cost, high speed, large capacity non-blocking switching architecture. In this paper, our focus is on developing parallel algorithms for routing which will ensure high-speed internet connectivity and at the same time making the system to be cost effective.

scholarly journals Evaluation and Comparison of Hybrid Wing VTOL UAV with Four Different Electric Propulsion Systems

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 256
Author(s):  
Jianan Zong ◽  
Bingjie Zhu ◽  
Zhongxi Hou ◽  
Xixiang Yang ◽  
Jiaqi Zhai
Keyword(s):  
Fuel Consumption ◽  
Electric Propulsion ◽  
Low Noise ◽  
Urban Traffic ◽  
Aviation Industry ◽  
Propulsion Systems ◽  
Performance Requirements ◽  
Vtol Uav ◽  
Battery Energy ◽  
Selection Of

Electric propulsion technology has attracted much attention in the aviation industry at present. It has the advantages of environmental protection, safety, low noise, and high design freedom. An important research branch of electric propulsion aircraft is electric vertical takeoff and landing (VTOL) aircraft, which is expected to play an important role in urban traffic in the future. Limited by battery energy density, all electric unmanned aerial vehicles (UAVs) are unable to meet the longer voyage. Series/parallel hybrid-electric propulsion and turboelectric propulsion are considered to be applied to VTOL UAVs to improve performances. In this paper, the potential of these four configurations of electric propulsion systems for small VTOL UAVs are evaluated and compared. The main purpose is to analyze the maximum takeoff mass and fuel consumption of VTOL UAVs with different propulsion systems that meet the same performance requirements and designed mission profiles. The differences and advantages of the four types propulsion VTOL UAV in the maximum takeoff mass and fuel consumption are obtained, which provides a basis for the design and configuration selection of VTOL UAV propulsion system.

scholarly journals PREMIUM YACHT PROPULSION FOR EXCLUSIVE PERFORMANCE

2019 ◽  
Author(s):  
A Witschel
Keyword(s):  
Fuel Consumption ◽  
Low Noise ◽  
Operating Costs ◽  
Shallow Waters ◽  
Propulsion Systems ◽  
Propulsive Efficiency ◽  
Course Stability ◽  
Wide Range ◽  
Overall Efficiency ◽  
Reduced Emissions

SCHOTTEL offers a wide range of main and auxiliary propulsion systems for yachts. This paper will present characteristics of different propulsion solutions: The 5-bladed controllable pitch propeller for highest propulsive efficiency for changing speed or load or the EcoPeller with best values in overall efficiency and course stability. It provides unprecedented performance and ensures that its owners benefit from low fuel consumption and thus reduced emissions and operating costs. Thanks to an installation flush with the hull, the pump jet is ideal for operation in extremely shallow waters. It can be used as manoeuvring aid, additional booster or take-home device. Low-vibration and low-noise rim thruster enables more comfort on board.

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

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